Group of elements for constructing gas spring and corresponding safety system

Abstract

A gas spring (100) comprising: a first fixing element (1) equipped with a side wall (11) and an abutment surface (12); a second hollow movable element (2) equipped with a side wall (21) and an upper closure element (22) defining a recess and configured to slide outwardly from the side wall of the first element (1) to allow the spring (100) to transition from an extended configuration to a compressed configuration; a gasket (4) adapted to increase the tightness of the gas spring (100). The side wall (21) and the upper closure element (22) are two different elements, and the upper closure element (22) has a shaped profile configured to abut the side wall (21) and configured to ensure that a gasket (4) is accommodated between the side wall (21) and the upper closure element (22).

Description

[0001] Specific description

[0002] The invention relates to a component assembly for constructing a gas spring and a corresponding safety system. Technical Field

[0003] The present invention belongs to the technical field of industrial springs, in particular to the technical field of systems and components constituting gas springs with safety functions. Background Art

[0004] Gas springs typically include:

[0005] - a fixed body, such as a column;

[0006] - a movable part, also called a rod;

[0007] - possible guide means for the rod;

[0008] - one or more sealing elements;

[0009] -The component that introduces gas into the interior of the column, also known as the loading valve.

[0010] Currently, the most important aspects in this field are those related to the ease of production and the safety of these mechanical devices.

[0011] In particular, a rather important aspect is the quality of the processing and the thickness of the inner wall of the gas spring, as the smoother and more uniform the wall, the better the performance of the gas spring.

[0012] Furthermore, if the wall thickness of the aforementioned gas spring can be reduced, the amount of material used to manufacture the gas spring itself can be limited.

[0013] Once a spring is put into continuous operation, it is not uncommon for it to suffer damage and deterioration due to normal wear or due to use under conditions of service that were not considered during the design phase or due to improper use, as well as due to completely accidental events.

[0014] An example of improper use is subjecting a spring to excessive stroke. "Excess stroke" refers to a stroke greater than the maximum stroke calculated during the design phase. In this case, shocks occur between the fixed and movable parts of the spring. These shocks can damage the spring and the equipment it is mounted or used with.

[0015] It is well known that, over time, improvements in the efficiency of the thrust element generally result in an increase in the maximum load that a gas spring can withstand. This is almost always achieved by increasing the gas pressure inside the spring itself.

[0016] Modern gas springs can withstand pressures reaching even greater than the initial values ​​of 180-200 bar and must be fully taken into account by designers, production and / or maintenance personnel as well as by users who use them as part of their activities.

[0017] It is therefore necessary to avoid damage or deterioration of the spring itself, and special attention must be paid to those types of damage that often affect the component but do not lead to its immediate breakage.

[0018] For example, damage that is minor and / or not detectable by direct visual inspection does not allow the user to identify the damaged gas spring and at least implement preventive measures such as, for example, replacing the damaged part or disposing of the piece.

[0019] If we further consider that gas springs often support cyclical loads, the eventual breakage of a damaged spring can lead to unpredictable and sudden accidents, with considerable risks for workers and operators in the vicinity of the broken spring. The consequences of such an accident can be very serious, resulting in varying degrees of injury and even death.

[0020] Since the evolution of these phenomena is difficult to assess, there is an urgent need to ensure adequate safety conditions in the field, regardless of the technology available to operators in the field to perform the various inspections.

[0021] In the case where the spring is already in an extra stroke state, the collision between the movable part and the fixed part of the spring cannot ensure complete release of the gas.

[0022] For example, a gas spring washer may wear or break without being noticed from the outside by the operator.

[0023] In known solutions, even if the washer is damaged, it will remain very close to its seat inside the spring when the spring is subjected to excessive stroke conditions, with the possibility of re-engagement. This will only allow a partial discharge of gas, potentially allowing the spring to continue to operate in the event of a break, posing a considerable risk.

[0024] Therefore, it is crucial to provide the gas spring with a secondary safety mechanism that can function in the event of a failure of the primary safety mechanism, which can prevent component breakage.

[0025] Purpose of the Invention

[0026] The object of the present invention is therefore to provide a set of elements for constructing a gas spring and a corresponding safety system capable of resolving the above-mentioned drawbacks and critical problems.

[0027] In particular, a first object of the invention is to construct a gas spring with a corresponding safety system which intervenes in the event of exceeding the maximum stroke limit foreseen for the gas spring itself.

[0028] Furthermore, another object of the invention is to ensure that the gas is released from the spring in the event of a collision between its components and therefore in the event of an excess stroke thereof.

[0029] Another object of the invention is to provide a gas spring with a corresponding safety system which is easier to produce and assemble.

[0030] Another object of the present invention is to construct a gas spring that allows the washer to disengage and prevents it from reengaging.

[0031] These and other objects are achieved by a set of elements for constructing a gas spring and a corresponding safety system according to the appended independent claims.

[0032] More detailed technical features are mentioned in the attached dependent claims. Summary of the Invention

[0033] Therefore, the object of the present invention is a gas spring comprising: a first fixed element, which is provided with a first side wall and an abutment surface; a second hollow movable element, which is provided with a second side wall and an upper closing element, which defines a recess and is configured to slide outward from the first side wall of the first element so as to transform the spring from an extended configuration to a compressed configuration; a washer, which is suitable for increasing the tightness of the gas spring, wherein the second side wall of the second element and the upper closing element are two different elements, and the upper closing element has a formed profile, which is configured to abut the second side wall, thereby ensuring the accommodation of the washer between the second side wall and the upper closing element.

[0034] This advantageously makes it possible to reach the inner surface of the base wall and the inner surface of the second side wall even in the case of very deep springs, facilitating all necessary handling.

[0035] According to the present invention, the forming profile of the upper closing element of the second element includes: a first part, which is equipped with a first diameter and a first surface, which is outward from the spring surface and located in a first horizontal plane; a second part, which is equipped with a second diameter and a second surface, which is outward from the spring surface and located in a second horizontal plane, wherein the second diameter is larger than the first diameter; a third part, which is equipped with a third diameter and a third surface, which is outward from the spring surface and located in a third horizontal plane, wherein the third diameter is larger than the first diameter and smaller than the second diameter, and wherein the third surface is suitable for receiving the second end of the side wall of the second element in abutment.

[0036] This configuration advantageously makes it possible to avoid a threaded connection between the two elements, since pressure alone will hold the upper closing element in place.

[0037] In a preferred embodiment, the upper closing element of the second element has a fourth portion with a fourth diameter and a fourth surface facing outward from the spring and situated in a fourth horizontal plane, the fourth diameter being smaller than the third diameter of the base wall itself. This embodiment allows for an improved abutment between the upper closing element of the second element and the side wall.

[0038] Again according to the invention, the side wall of the second element comprises a first end intended to abut against the abutment surface of the first element and a second end intended to abut against the upper closing element of the second element; the second end of the side wall of the second element is inclined at approximately 90° relative to the side wall and protrudes toward the interior of the spring, the second end being suitable for maintaining the upper closing element in an appropriate position.

[0039] In this configuration, the second side wall can advantageously be produced easily and quickly, since it can be obtained from the tube.

[0040] According to the present invention, the second element includes a through-hole defined by the second end, the through-hole having an inner diameter greater than or equal to the first diameter of the upper closure element, so that the first portion of the upper closure element can pass through the through-hole of the second element. This feature, combined with the fact that the second end of the second side wall defines the through-hole, facilitates separation between the upper closure element and the side wall of the second element, if necessary.

[0041] Furthermore, the inner diameter of the through hole of the second element is smaller than the third diameter of the third portion of the upper closing element of the second element, thereby forming a space for accommodating a gasket between the second end of the side wall and the second portion of the upper closing element.

[0042] This advantageously allows obtaining tightness at a critical point of the spring, since, in critical conditions, the gasket will be in a position close to the gas exit point; from this position, once tightness is lost beyond the maximum stroke limit, the gasket will be sucked in by the outgoing gas flow itself and expelled by the spring.

[0043] Furthermore, also according to the present invention, the thickness of the second end of the side wall of the second element is less than the distance between the first and third surfaces of the upper closure element of the second element itself, so that when the spring is fully inflated with gas, the first portion of the upper closure element at least partially protrudes from the second end of the second side wall. In this manner, once the second side wall abuts the abutment surface of the first element, and when the maximum stroke limit is exceeded, the upper closure element moves relative to the second side wall and continues to descend, so that the outermost surface of the upper closure element and the outermost surface of the second end become coplanar. In this manner, tightness is advantageously lost, facilitating the release of gas and avoiding potentially dangerous accidents for the operator and the equipment on which the spring itself is mounted. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The invention will now be described by way of non-limiting examples according to some preferred embodiments of the invention with the aid of the accompanying drawings, in which:

[0045] - FIG1 is a cross-sectional view of a gas spring including a safety system according to the invention;

[0046] - Figures 2A-2C show details of the gas spring when the sealing element is released from the gas spring of Figure 1A. DETAILED DESCRIPTION

[0047] In the following, reference is made to the gas spring described by way of example in patent document WO 2022054116 A1.

[0048] This does not mean that the invention cannot be applied to other types of gas springs having a simpler or in any case a different configuration.

[0049] With reference to the mentioned figures, preferred embodiments of a component set for constructing a gas spring and a corresponding safety system according to the invention are shown.

[0050] 1 , a gas spring according to the present invention is generally indicated by 100 and comprises a hollow fixed body 1 or cylinder and a hollow movable body 2 or rod having a recess opposite to said cylinder 1 .

[0051] Rod 2 is configured to slide outwardly from column 1, always maintaining contact, from an extended or open configuration to a compressed or closed configuration.

[0052] Advantageously, the column 1 and the rod 2 comprise respective side walls and respective base walls or closing elements, as will be better seen below.

[0053] In particular, the column 1 comprises a side wall 11 and an end-of-stroke or abutment surface 12 perpendicular to the side wall 11 ; the rod 2 comprises a corresponding side wall 21 and an upper closing element 22 .

[0054] Advantageously, according to the invention, the upper closing element 22 and the side wall 21 of the rod 2 are two distinct parts in order to facilitate production and to provide an additional safety system for the spring 100 , as will be more clearly described below.

[0055] The upper closing element 22 is manufactured with a shaped profile configured to abut against the side wall 21 and ensure the accommodation of the gasket therebetween.

[0056] In particular, the upper closing element 22 has:

[0057] a first portion 221 provided with a first diameter and a first surface facing outwards from the spring and situated in a first horizontal plane;

[0058] a second portion 222 provided with a second diameter and a second surface facing outwards from the spring and situated in a second horizontal plane, the second diameter of the second portion 222 being greater than the first diameter;

[0059] a third portion 223 provided with a third diameter and a third surface facing outwards from the spring and situated in a third horizontal plane, the third diameter of the third portion 223 being greater than the first diameter and smaller than the second diameter;

[0060] a fourth portion 224 provided with a fourth diameter and a fourth surface facing outwards from the spring and situated in a fourth horizontal plane, the fourth diameter of the fourth portion 224 being smaller than the third diameter of the third portion 223 .

[0061] The second portion 222 is positioned lower than the other portions 221 , 223 , 224 and is adapted to receive at least one gasket on the second surface.

[0062] In the second embodiment, the upper closure element 22 comprises only the first portion, the second portion and the third portion.

[0063] Due to the gas pressure inside the spring 100 exerted on the inner surface of the upper closing element 22 itself, the upper closing element 22 is held in place, ensuring correct sealing and in this way preventing it from detaching from the side surface 21 .

[0064] In particular, this coupling is ensured by gas pressure, which exerts an upward force on the inner surface of the upper closing element 22 and a downward force on the upper surface of the gasket fixed to the side wall 21 and in contact with the side surface 11, which force is then transmitted to the side wall 21 itself. These two forces have opposite directions and ensure the coupling and tightness between the side wall 21 and the upper closing element 22.

[0065] The side wall 21 is perpendicular to the upper closing element 22 and comprises a first end 211 intended to abut against the abutment surface 12 of the column 1 and a second end 212 intended to abut against the upper closing element 22 of the rod 2 itself.

[0066] In more detail, the second end portion 212 is inclined at approximately 90° relative to the side wall 21 and projects inwardly to hold the upper closure element 22 in place when the gas is inside the spring 100 .

[0067] In more detail, when the upper closing element 22 is correctly in position and abuts the side wall 21 , the third portion 223 of the upper closing element 22 is in contact with the second end 212 of the rod 2 by means of the washer 4 .

[0068] This washer 4 ensures the correct tightness of the spring 100 , preventing the gas inside it from escaping from the contact portion between the upper closing element 22 and the side wall 21 of the stem 2 .

[0069] The inner diameter of the second end 212 is smaller than the third diameter of the third portion 223 of the upper closing element 22 , so that the washer 4 is placed between the second portion 222 of the upper closing element 22 and the second end 212 of the side wall 21 of the rod 2 .

[0070] In particular, the gasket 4 is in contact at the bottom with the second portion 222 of the upper closing element 22 , at the top with the second end 212 of the side wall 21 , and laterally with the fourth portion 224 of the upper closing element 22 .

[0071] Advantageously, this configuration with two distinct elements allows the operator to perform the assembly operation in a more convenient and rapid manner.

[0072] Furthermore, the two-element construction also enables advantages to be obtained during the machining and production phases of the spring, since it allows easier access to the inner surfaces of the side walls 21 and of the upper closing element 22 , in order to carry out the treatments necessary for the correct operation of the spring 100 , such as calibration or threading.

[0073] Preferably, as shown in FIG1 , the side wall 11 and the base wall of the column 1 may also be two different components fixed together.

[0074] The column 1 and the rod 2 are made in such a way that the inner surface of the side wall 21 of the rod 2 can slide outward but is in contact with the outer surface of the side wall 11 of the column 1 .

[0075] In operation, when the spring 100 transitions from the extended configuration to the compressed configuration, the rod 2 slides downwards, reducing the internal volume of the spring 100 and thus increasing the internal pressure of the gas within the spring 100 itself.

[0076] When the rod 2 completes its stroke and reaches the end-of-stroke state, the first end 211 of the side wall 21 abuts against the abutment surface 12 of the column 1, thereby preventing the rod 2 from moving further downward.

[0077] In this case, as shown in FIG. 2A , the upper surface of the closing element 22 facing outward from the spring is at a higher level than the fifth horizontal plane defined by the second end 212 of the side wall 21 .

[0078] In other words, due to the thrust of the gas within the spring itself, the upper surface of the first portion 221 of the upper closing element 22 facing outward from the spring is maintained at a higher height than the second end 212 of the side wall 21 .

[0079] During its life, the spring passes from an extended position to a compressed position, wherein, respectively, the first end 211 of the side wall 21 moves away from the abutment surface 12 of the column 1 and the first end 211 of the side wall 21 moves closer to the abutment surface 12 of the column 1 .

[0080] In the event that the spring is mistakenly brought to a position of extra stroke, in which the first end 211 of the side wall 21 collides with the abutment surface 12 of the cylinder 1, the side wall 21 will come to a stop, whereas the upper closing element, constrained to this side wall only by the gas present in the spring 100, will be free to continue its downward stroke against the thrust exerted by the gas itself.

[0081] As shown in Figure 2B, when the fourth portion 224 of the upper closing element 22 is at the same height as or lower than the inner surface of the second end 212 of the side wall 21, the gasket 4 is no longer compressed between the two parts 21 and 22 of the rod 2 and is separated from the corresponding surface, thereby allowing the gas to be partially released from the spring 100.

[0082] Finally, as shown in Figure 2C, when the upper surface of the first part 221 of the upper closing element 22 is coplanar with the second end 212 of the side wall 21, that is, when the upper surface is at the same height as the outer surface of the second end 212 of the side wall 21, the upper closing element 22 is no longer in contact with the side wall 21 of the rod 2.

[0083] In this case, due to the gas pressure inside the spring 100 , the gasket 4 , which has lost its tightness at a previous stage, is pushed upwards by its flow and is expelled from the spring 100 itself along the arrow shown in FIG. 2C .

[0084] Once the washer 4 comes out, the tightness of the spring 100 is irreversibly and completely lost, so that the gas can be completely released, thereby avoiding the reuse of the spring 100 and the occurrence of potential accidents.

[0085] In this way, an operator can immediately notice a break in the spring 100, thereby preventing the spring from being subjected to further handling and avoiding dangerous inspection operations that could lead to accidents or even serious injuries while the spring is damaged and still has pressurized gas inside.

[0086] In fact, in the absence of internal pressure in the spring 100 , the upper closing element 22 will clearly detach from the side wall 21 .

[0087] Advantageously, the present invention allows the production of gas springs 100 of any size and easier production, for example allowing for weight reduction and thus material savings.

[0088] In particular, manufacturing the rod 2 in two distinct parts allows the side wall 21 to be produced directly from the tube, unlike current methods which consist of drilling a solid cylinder with the result that there is a waste of material and the risk of breaking the part machined inside it.

[0089] In fact, since, in this embodiment shown in the accompanying drawings, the rod 2 is substantially similar to a hollow cylinder, a lathe will be able to easily operate and shape the two ends and the central portion of the rod 2 .

[0090] Furthermore, a standard upper closure element 22 can be manufactured that can be used with a variety of springs 100 in combination with side walls 21 of different lengths.

[0091] From the above description, the characteristics and advantages of the set of elements for constructing a gas spring and the corresponding safety system, object of the present invention, are clear.

[0092] Finally, it is clear that many other modifications could be made to the device in question without departing from the principle of novelty inherent in the inventive idea, just as it is clear that in a practical embodiment of the invention the materials, shapes and dimensions of the details shown can be any desired and that they can be replaced by other equivalents.

[0093] In cases where features and techniques mentioned in any claim are followed by reference numerals, the sole purpose of including such reference numerals is to increase the intelligibility of the claims and, therefore, such reference numerals have no limiting effect on the interpretation of each element identified by such reference numerals by way of example.

Claims

1. A gas spring (100), comprising: a first fixing element (1), the first fixing element being provided with a first side wall (11); a second hollow movable element (2) provided with a second side wall (21) and an upper closing element (22), the upper closing element defining a recess and configured to slide outwardly from the first side wall (11) to transition the spring (100) from an extended configuration to a compressed configuration; a washer (4), said washer being adapted to increase the tightness of said gas spring (100), wherein the second side wall (21) and the upper closing element (22) of the second element (2) are two different elements, and the upper closing element (22) has a shaped profile, the shaped profile being configured to abut against the second side wall (21) and to receive the gasket (4) in a receiving space between the second side wall (21) and the upper closing element (22), The gas spring (100) is characterized in that the shaped profile comprises: a first portion (221) provided with a first diameter and a first surface facing outward from the spring and lying in a first horizontal plane; a second portion (222) having a second diameter and a second surface facing outward from the spring and located in a second horizontal plane, the second diameter being greater than the first diameter; a third portion (223) provided with a third diameter and a third surface facing outward from the spring and located in a third horizontal plane, the third diameter being larger than the first diameter and smaller than the second diameter, the third surface being adapted to abuttingly receive the second end portion (212) of the second side wall (21).

2. The gas spring (100) according to claim 1, characterized in that The upper closure element (22) has a fourth portion (224) provided with a fourth diameter smaller than the third diameter and a fourth surface facing outward from the spring and located in a fourth horizontal plane.

3. The gas spring (100) according to claim 1 or 2, characterized in that The second side wall (21) of the second element (2) comprises a first end (211) and a second end (212), the first end being intended to abut against an abutment surface (12) associated with the first element (1), the second end being intended to abut against the upper closing element (22) of the second element (2), and wherein the second end (212) is inclined at approximately 90° relative to the side wall (21) and projects towards the interior of the spring, suitable for maintaining the upper closing element (22) in position.

4. The gas spring (100) according to claim 3, characterized in that The second element (2) is provided with a through hole having a fifth inner diameter greater than or equal to the first diameter of the upper closing element (22), such that the first portion (221) of the base wall can pass through the through hole, the through hole being defined by the second end (212).

5. The gas spring (100) according to claim 4, characterized in that The fifth inner diameter is smaller than the third diameter, thereby forming a space suitable for accommodating the gasket (4) between the second end portion (212) and the second portion (222) of the upper closing element (22).

6. The gas spring (100) according to any one of claims 3 to 5, characterized in that The thickness of the second end portion (212) is smaller than the distance between the first surface and the third surface of the upper closing element (22).

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